1. Field of the Invention
The present invention relates generally to broadcast services, and in particular, to a method for more efficiently providing broadcast services in a mobile communication system using code division multiple access (hereinafter referred to as “CDMA”) technology.
2. Description of the Related Art
In the future, communications environments will undergo rapid changes regardless of wired/wireless region or country. In particular, the communications environment, such as IMT-2000 (International Mobile Telecommunication-2000), tends to synthetically provide users with various information needs including image and voice information on a real-time basis. With the development of mobile communication technology, even in a cellular wireless communication system or PCS (Personal Communications System) mobile communication system, a mobile station (MS) has the ability to not only simply perform voice communication but also to transmit text information and to receive broadcast services.
At present, 3GPP2 (3rd Generation Partnership Project 2) considers the efficient utilization of various service media and resources for a broadcast service in a mobile communication system. Such a broadcast service is performed by unidirectionally transmitting high-speed forward data without receiving reverse feedback information from a mobile station. A broadcast service in a mobile communication system is characterized in that a plurality of base stations (BSs) simultaneously transmit the same data stream. This is conceptually similar to a general television broadcasting service.
If a common channel is designed so as to guarantee the same performance even at a cell boundary, cell capacity is excessively wasted. Therefore, in a 3rd generation mobile communication system, a structure of a supplemental channel proposed as a dedicated channel for a packet data service is partially modified to realize high-speed transmission for a broadcast service. The supplemental channel uses a common long code mask instead of a long code mask dedicated to a user, for a broadcast service. During a broadcast service, autonomous handoff not requiring feedback information from a mobile station and outer coding are performed to guarantee performance higher than or equal to that of an existing common channel.
In an existing wireless broadcast service under discussion, a broadcast service provider is limited to a specific broadcast server or a contents server designated by a common carrier, so mobile stations can only passively receive the broadcast service. Therefore, the service provider cannot charge for the broadcast service according to its service time or quantity. In addition, because the same data stream is simultaneously transmitted from several base stations as stated above, network resources for a broadcast service must be assigned to all the base stations, preventing efficient utilization of resources.